The Anita is considered to be the first electronic desktop-calculation
machine of the world. A prototype of the machine
can be found in the London Museum of Science.
In its 1/1962 issue the magazine "ELEKTRONIK" published the following
newsflash:
An electron calculator with the size of a typewriter is now offered
by a London company. It can be used for addition, subtraction,
multiplication and division. An automatic control equipment is
integrated for checking the results. The replies are given in
illuminated cyphers in a very short time.
And again in a later issue:
Some times ago, we could call our readers' attention to the first
electronic desktop-calculation machine in the world. ... The improved
construction carries now the name Anita Mark C/VIII. Here it's about a
... calculator, working completely silent with an electronic
calculation speed, that is in the range of milliseconds. .. It is
amazing that at a presentation, after the input of the numeric values,
there is no typical rattling sound of electro-mechanic calculation
machines but the display quickly and silently shows the result.
Previously, the constructor Norman Kitz had contributed to the Brititsh
computer of the 1st generation, the Pilot ACE.
In the patent specification, the ANITA is even described with a motor
step-switch-counter, which is replaced by an electronic ring-counter at
the final version.
The triode systems work as an oscillator and pulse shaper, the
cold cathode relay tube as flip-flops(1 relay tube corresponds to 1
Thyristor in semiconductor technology and saves or counts a bit.).
In the thermionic technology, the Dekatron corresponds an
'integrated circuit'. The rectifiers, made of selenium, serve as logic
gates and clamping diodes, the transistor is obviously a patch.
The frequency is 3kHz. So the ANITA is ten times faster than a fast
mechanic calculation machines.
Just for the 12-digit accumulator, 120 (about 2/3) of the existing
relay tubes are used. That's why the machine only has one electronic
register. It's second register, the operand and entry register is the
'complete keyboard', a relic from the times of the mechanic calculation
machines. In contrast, a 'classic' mechanic calculation machine owns
three to four registers: accumulator, entry register, rotation-counter
and possibly multiplicand count register.
The ANITA cost as much as a VW-Beetle in 1961.